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welcome to controllers tech this is
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another video covering the raspberry pi
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and today we will see how to use analog
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to digital conversion in pi pico
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i will first cover the adc part where we
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will read the voltage from a
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and later we will see the internal
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temperature sensor which also relies on
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here is the pin out of the picot
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this is a-d-c-0 a-d-c-1
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and a-d-c-2 this pin is the reference
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voltage for the a-d-c
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you can connect the reference voltage
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if not connected then the reference will
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considering the input to pico is greater
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here i will use the potentiometer first
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this is how the connection looks like
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the v-c-c is connected to 3.3 volts from
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ground to ground and the output from the
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is connected to the pin 26 of the pico
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which is basically the a-d-c-0
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let's see the r-p 20-40 data sheet once
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go to the a-d-c section
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here it's mentioned that this chip of 5
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out of them 4 are the regular ones
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you can see them they are available on
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but the 5th one is connected to the
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also the adc have the resolution of 12
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now if we look into the pico python sdk
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it's mentioned here that although the
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resolution is 12 bits
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but in micro python this will be handled
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so this a-d-c behaves as a 16-bit adc in
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that's all for the basic details about
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let's start the thunni ide now
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the device is not connected so i will
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and press stop and you can see the
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let's write our program
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first of all we will import the adc from
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also import the time for delay purposes
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now let's initialize the adc0 which is
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start an infinite loop here first of all
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we will read the adc value and convert
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it to the respective voltage
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this idea is very simple the adc reading
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of 0 corresponds to zero volts
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and the reading of 65 535 corresponds to
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so based on this we can convert our
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reading to the voltage
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now we will print this voltage to the
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and sleep for 10 milliseconds
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now let's save this inside our picot
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it saved successfully so run it now
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you can see the voltage values are being
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printed on the console
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let's rotate the potentiometer now
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this is the maximum i can rotate the
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and it reads 3 point 3 volts here
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now i am rotating in another direction
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and the voltage is decreasing
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its almost zero at the minimum point
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you can see how the voltage is changing
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based on the rotation
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this is because the potentiometer is
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like a variable resistor
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whose resistance varies when rotated
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that's why the voltage output from the
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also varies we can also bring the
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concept of angle of rotation here
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this particular potentiometer can rotate
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that means when the voltage is 3.3 volts
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the angle is 300 degrees
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and when the voltage is zero the angle
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again we will use the ratio logic and
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write one formula to convert the voltage
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you can see how the angle is changing
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this is it for the potentiometer now we
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will see the internal temperature sensor
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let's delete this code first we will
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initialize the a-d-c-4 for the
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because that's the one connected to it
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again write an infinite loop let's see
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20-40 data sheet again
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here go to the temperature sensor
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as you can see here is the formula to
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convert the adc voltage to the
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let's copy it and paste directly in our
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as the formula require the adc voltage
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let's calculate the adc voltage first
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i am going to call it temp
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print the temperature now and add a
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let's save it and run
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you can see the temperature on the
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note that this is in degrees celsius and
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you can use the conversion formula to
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convert it to the fahrenheit
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you can see here if i touch the core the
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it will take some time to go back to
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this is it for this video i hope
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things were clear i will try to bring
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and interrupt videos for the adc in the
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you can download the code from the
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github the link is in the description
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keep watching and have a nice day ahead
